Asus PCH-DL - Manual (Page 24)

2-6 Chapter 2: Hardware information
2.3 Central Processing Unit (CPU)
2.3.1 Overview
The motherboard comes with dual surface mount 604-pin Zero Insertion
Force (ZIF) sockets. The sockets are designed for the Intel
® Xeon™
Processor in the 604-pin package with 1MB/512KB L2 cache.
2.3.2 Installing the CPU
Note in the above illustration that the CPU has a gold triangular mark on
one corner. This mark indicates the processor Pin 1 that should match a
specific corner of the CPU socket.
If installing only one CPU, use CPU socket 1 to ensure system
stability..
Socket for CPU1
Socket for CPU2
PCH-DL
PCH-DL Socket 604
Prestonia
Gold Arrow